Coprocessor instructions progress down the ARM7TDMI-S pipeline
in step with the coprocessor pipeline. A coprocessor instruction
is executed if the following are true:
The coprocessor instruction has reached
the Execute stage of the pipeline. (It might not if it was preceded
by a branch.)
The instruction has passed its conditional execution
tests.
A coprocessor in the system has signalled on CPA and CPB that
it is able to accept the instruction.
If all these requirements are met, the ARM7TDMI-S signals
by taking CPnCPI LOW, committing
the coprocessor to the execution of the coprocessor instruction.
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